As stereo and multi-channel home entertainment systems expand their functionality to incorporate voice communication and multiple simultaneous media streams, along with more conventional playback applications, a problem arises in that new audio streams (e.g., ring tones, voice, a “picture-in-picture” audio stream, etc.) need to be dynamically integrated into the rendered audio. The simplest solution is just to replace one set of audio signals with another, either manually or automatically, but listeners may prefer the option of attending to both the old and new audio streams simultaneously. This can be easily engineered by mixing the audio signals together, but listeners may then find it difficult to differentiate between the overlapping audio streams.
There is a need for an audio rendering system that actively facilitates “auditory multitasking” by automatically managing the simultaneous presentation of multiple audio streams so as to promote preferential attention to one of these streams. There is a further need for this facilitation to be applicable to stereo and multi-channel audio streams, and for it to be effective both for audio rendered via speakers and for audio rendered via headphones. Existing systems do not allow this to be achieved.